A new clinical trial confirms that Fluzone Hi-Dose better protects seniors against influenza. When should you get your dose?

As health experts gear up for this year’s flu season, results from a large clinical trial show that seniors are best protected with a high-dose vaccine.

Sanofi’s Fluzone Hi-Dose was fast-tracked through the FDA approval process in 2009 on the condition that they test the vaccine in a study to confirm its efficacy.

A clinical trial of 30,000 seniors over the age of 65 showed Fluzone Hi-Dose was 24.2 percent more effective in preventing influenza than the standard vaccine, the company said this week.

High-dose flu shots like Fluzone Hi-Dose were specifically designed for people over the age of 65, who run a higher risk of complications from the flu virus and whose immune systems are comparatively weaker.

The high-dose flu shot is covered by Medicare.

The simple answer is sooner rather than later.

The flu season changes every year. While it typically peaks in January or February, in years past it has begun as early as October and calmed down as late as May.

The CDC recommends getting the vaccine as soon as it becomes available, as its protection lasts throughout the flu season.

Vaccine manufactures are expected to make 135 to 139 million vaccination doses this year. During last year’s flu season, which affected 48 states, many areas reported vaccine shortages in February because of rushes when the flu season’s peak was worse than expected.

The flu shot is offered at doctor’s offices, pharmacies, and other healthcare centers nationwide.

It’s always difficult to predict the severity of a flu season.

Experts at the CDC say each season’s timing, severity, and length vary by year. Last year’s flu season appeared earlier in the year and involved many more cases before it peaked in February.

The 2012-13 flu season led to 12,343 hospitalizations from Oct. 1 to April 30, the CDC reported. Each year, between five and 20 percent of the U.S. population contracts the flu virus, resulting in an average of 200,000 hospital visits, according to Flu.gov, the government flu informational site.

During last year’s season, half of all children in the U.S. were vaccinated, as well as a third of all adults.

While it would be ideal to keep our body’s defenses as vigorous as they were when we were young, our immune system loses strength as we age.

While the CDC recommends that everyone over the age of 6 months—with few exceptions—be vaccinated, those over the age of 50 are especially susceptible to complications from the seasonal flu virus. Residents of nursing homes or other care facilities are also strongly encouraged to get a flu vaccination.

A major flu-related concern for the elderly is the risk of developing pneumonia, which can be fatal if left untreated.